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[v3,3/4] powerpc/pseries: register pseries-wdt device with platform bus

Message ID 20220713202335.1217647-4-cheloha@linux.ibm.com
State New
Headers show
Series pseries-wdt: initial support for H_WATCHDOG-based watchdog timers | expand

Commit Message

Scott Cheloha July 13, 2022, 8:23 p.m. UTC
PAPR v2.12 defines a new hypercall, H_WATCHDOG.  The hypercall permits
guest control of one or more virtual watchdog timers.

These timers do not conform to PowerPC device conventions.  They are
not affixed to any extant bus, nor do they have full representation in
the device tree.

As a workaround we represent them as platform devices.

This patch registers a single platform device, "pseries-wdt", with the
platform bus if the FW_FEATURE_WATCHDOG flag is set.

A driver for this device, "pseries-wdt", will be introduced in a
subsequent patch.

Signed-off-by: Scott Cheloha <cheloha@linux.ibm.com>
 arch/powerpc/platforms/pseries/setup.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)
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diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index ee4f1db49515..dd9d3f500cff 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -14,6 +14,7 @@ 
 #include <linux/cpu.h>
 #include <linux/errno.h>
+#include <linux/platform_device.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
@@ -169,6 +170,18 @@  static void __init fwnmi_init(void)
+ * Affix a device for the first timer to the platform bus if
+ * we have firmware support for the H_WATCHDOG hypercall.
+ */
+static __init int pseries_wdt_init(void)
+	if (firmware_has_feature(FW_FEATURE_WATCHDOG))
+		platform_device_register_simple("pseries-wdt", 0, NULL, 0);
+	return 0;
+machine_subsys_initcall(pseries, pseries_wdt_init);
 static void pseries_8259_cascade(struct irq_desc *desc)
 	struct irq_chip *chip = irq_desc_get_chip(desc);